Pneumatic tube terminal



Nov. 1, 1938 J. M. SCANLAN PNEUMATIC TUBE TERMINAL Original Filed March 7, 1934 2 Sheets-Sheet 1 Y4; ATTORNEY v INVENTO mo JIHIIIHHHHP 0 Nov. 1, 1938. YJ, M, SCANLAN 2,135,355"

PNEUMATIC TUBE TERMINAL Original Filed March 7, 1934 2 Sheets-Sheet 2 I HTS: Z 8 llllllllllllllll m N o E LO h 0 cu m 1 I 1', l E

1- NVENTOR w M BY 7: ATTORm Patented Nov. 1, 1938 I UNITED STATES PATENT OFFICE PNEUMATIC TUBE TERMINAL Joseph M. Scanlan, Syracuse, N. Y., assignor, by mesne assignments, to The Lamson Company, Syracuse, N. Y., a corporation of Massachusetts Application March 7, 1934, Serial No. 714,362 Renewed October 28, 1936 17 Claims. (01. 243-12) This invention relates to pneumatic tube sys- Figure 6 is a vertical section through the main tems in which a carrier is propelled through a control valve and associated parts. tube by the pressure of air being made greater at Referring now to the drawings, in which the one end of the carrier than at the other. It has invention is shown applied to a suction or vacuparticular reference to systems of this character um system, a typical transmission tube I is inadapted to handle large carriers for the transdicated inFigure 1. This tube is connected near mission of comparatively large documents or the its discharge end with a suction drum I I forming like. In systems of this sort it has been found part of suitable power equipment. The connecthat excessive noise and jarring of the apparatus tions between the tube It and the drum include at the delivery ends of the tubes takes place if pipes I2 and I3, the latter of which is connected 1Q satisfactory means is not provided for absorbing into the lower side of the tube II] at the point I4. the energy of the carriers prior to discharge. Ac- The pipe enters the tube at substantially Tight cordingly it has been an object of the present inangles to its axis at a point near the end, i. e., vention to provide for the cushioning of the carbeyond a bend in the tube which causes the reriers just prior to their discharge from the tubes maining end portion of the letter to incline dOWh- 15 so as to break the force of their delivery. wardly at a angle of about s a a More specifically the invention involves the proment is c at as e carrier passes the point vision of a door at the discharge end of each tube s ntinued movement toward the end of the normally retained in closed. position by a latch tube Will be insured y gravity, as Well as y the which is automatically released as the carrier apmomentum of the C 20 preaches the door. Suitable provision is also Between the p p s I2 and I3 there is Provided made for the ut m ti reg-engagement of th a control valve I5 of any suitable construction, latch after the carrier has been discharged and preferably f h pe ap d to allow a certain the door returned to its closed position. Also minimum W through t e tube When it is not coupled with the latch operating means is providactive and arranged to Provide 3 Carrie! 25 ed a connection for assisting in the control of the Felling fi W po the insertion of a carrier into main control valve by which the carrier impelling the receiving end of the tube- F this P p flow is regulated. This connection is such as to the Valve y include a p I5 Substantially bu insure the prompt closing of the control valve not fully Closed y a V v TO this Valve is when the carrier impelling flow is no longer reattached a stem I3, the end of Which is arranged 30 quired. to engage a set-screw I9. This screw may be While certain specific devices will be presently Suitably adjusted to maintain t Valve IT a s t di l d i d t il for accomplishing t foredistance ofi of its seat so as to create a desirable going purposes, it will be understood that in its minimum A spring 29 y be ve ent y broader aspects the invention encompasses widely Previded urging the Valve against its seat and 35 difierent means for accomplishing the same gentherefore urging the d of t te 8 a ainst eral results. Various objects and advantages of the Set-Screw This arrangement w pr vide the invention in addition to those already specifor a slight fiOW of air through he tube I0 Whenfied will be made apparent from the detailed deever the power equipment is O The stem I8 is scription of one form of the same which will now Slidably mounted in a Casing 2| divided into tWO 40 b given i conjunction t t accompanying enclosed chambers 22 and 23 by a diaphragm 24. drawings,in which; This diaphragm, at its mid-point, is secured to Figure 1 is a side elevation of the apparatus the stem An Opening 25 ugh the outer associated it t discharge end f a tube formside of the casing constantly admits air under atjng part of vacuum system mospheric pressure into the chamber 23. At fit- 45 Figure 2 is an enlarged view, in side elevation, s 26 having an open p e throu h it places of t lower end of th t the chamber 22 in communication with the Figure 3 is a front elevation of a portion of the P d of th t b as viewed along t line 3 3 of Now, when a carrier is introduced into the tube, 59 Figure 2, the flow of air into the tube is cut off and a slight 5 0 Figure 4 is a detail view of a portion of the latch Vacuum s ea e W hin the pipe I3. This, by control mechanism as seen along the line 4-4 of means of the passage through the fitting 26 serves Figure 2. to withdraw air from the chamber 22. The cham- Figure 5 is a side elevation of the detail shown her 23 at the opposite side of the diaphragm being 5 in Figure 4, and in constant communication with the atmosphere, ,5

' cause the valve I to be shifted away from its seat larger.

into the full open position indicated in Figure 1. A'carrier propelling suction or flow is thus produced. The carrier is propelled throughthetube by virtue of the atmospheric pressure acting upon its outer end and the sub-atmospheric pressure acting upon its inner end. .This condition exists until the carrier passes the point l4, after which it continues to move downwardly underits own momentum and under the force of gravity. I

I If no means were provided to break the force of the carrier, it would be discharged with such velocityland impact as to jar the apparatus severely and damage not only the equipment but the carriers themselves. The damage result' ing in this-way is'particularlyserious in dealing with carriers of the larger sizes. In'some installations the carriers may,"for example, be 8 x 12" in cross section and, say, 24 long, or even Such carriers when loaded may weigh as much as thirty pounds,or, more. The necessityof 'absorbingrthe energy of carriers of this size is especially great, Even carriers of smaller size will do considerable damage if not cushioned in some way to lessen the impact in the course of delivery from the tube. The devices illustrated for the purpose of breaking the force of the car, riers include a door 21- adapted to close the lower end of the tube Hi. This door is held against its seat by means of a latch 28 pivoted upon a bracket 29 secured to'the under side of 'a receiving chute 3|I.v An arm of the latch is connected to a rod 3| slidably mounted in a diaphragm casing 32. Within this casing there is mounted a diaphragm 33 secured to the rod and adapted to shift the latter in the manner to be presently explained. .A'spring34 within the diaphragm casing normally urges the diaphragm upwardly and toward the right in Figure 2 and thus urges the rod 3| in the same direction, tending to shift the latch into door-releasing position. On one side of the diaphragm '33 is a chamber 35 maintained constantly at atmospheric pressure by means of an opening through the casing. At the opposite side of the diaphragm'is a chamber 36 connected by means of pipes 31 and 38 with the suction drum A valve 39 in'this line may be provided to regulate the flow of air through the pipe 38 a and, by means of rod 3|, rock the latch into doorlocking position.

Between the pipe 31-and valve 39 there is provided a T-connection 40 having one branchconnected to a vertically extending pipe 4|. The upper end of this pipe terminates adjacent the tube l6 and is normally closed by means of a valve 42. This valve is carried by an arm 43 pivotally mounted upon a pin 44 carried by a bracket suitably secured to the tube. As the carrier 45 approaches'the door 21; it engages a tripelement 46 which extends through the wall of the tube into the path of the carrier. The trip ele- 'ment is secured to arod 41' rockably mounted in a bracket 48 carried by the tube. 'Adjacent the end of 'the rod'4'|, which extends 'to the side .of

The arrangement is such that as the trip element 46 is engaged by the carrier and forced outwardly, the arm 49 will engage the arm 53 and cause the valve 42 to be lifted from the end of the 7 pipe 4 I. This admits air under atmospheric pres- Therefore, the pressures on the two sides of the diaphragm 33 are equalized and the spring 34 V operates to release the latch 28.; It will be understood that as the carrier passes downwardly in the tube ID from the position shown in Figure 1,

gravity out of the end of the tube into the chute 30. A pad 5|, or other suitable form of buffer, may be provided at the end of the chute to receive the final impact of the carrier.

In order to insure the maintenance of the latch 28in tripped or released position, until the carrier has been fully discharged and thedoor re-" i turned to its closed position, additional air consure into the pipe and into the chamber 36.

nections are provided, These include a pipe '52 connected with the pipe 4| through a cross fitting 53. The free end of the pipe 52 is closed by means of a valve 54 carried by an arm 55 pivotally mounted upon a bracket suitably carried by the chute adjacent the door... An arm 56 connected with thearm'55 is arranged to be engaged by an arm'51 secured to a rod or rock shaft 58. This rod supports the door 21 by means. of arms 59 secured to the door and also to the rod. By the connections described, it will be apparent that when the door swings open,,the rod 58 will berocked and the: valve 54 lifted from its seat. This will admit air into the pipe 52 and pipe 4| so that even after the valve 42 is restored, upon the passage of the carrier beyond the trip element 46,{ air under atmospheric pressure will be maintained in the chamber 36. This condition will continue so long as the door is partly or fully open. However, upon the discharge of the carrier and the return of the door to its closed'position, the ends of. the pipes 4! and '52 will be closed and the suction acting through pipes .31 and 38 will create a partial vacuum within the chamber 36 and thus cause the latch to swing into its door-retaining position; Prior to reengagement of the latch, the door will be drawn and held against its seat by the suction within the tube Ill.

The purpose of the valve, 39 will now be made more clear. It must be adjusted to such a position that it will not permit sufficient leakage, to

overcome the effect of the air entering'thetube 4| through'the valves 42 and 54. In other words,

the leakage of air throughthevalve must not'be so great as-to prevent substantially atmospheric pressure being maintained in the chamber 36 whenever either one of the valves 42 and 54 is open. Onthe other hand, it should be great enough to insure rapid return of the latch to door-holding position after a carrier has been discharged.

' 7 Connections are provided for insuring the,

rapid closing of the main control valve upon the discharge of a carrier. These connections include a pipe 60 'joining'one side of the cross to shift the valve I! to its minimum flow position shown in Figure 6. If desired, the closing of the valve may be further insured by the provision of a vane 6| in the pipe l3. This vane may be attached to'a lever pivoted at 62 on the side of the pipe and carrying at its opposite end a valve 63 normally closing a port 64 communicating with the passage through the member 26. The sudden rush of air created upon the discharge of the carrier, as it passes the point It, impinging upon the vane 6|, will rock the lever to lift the valve 63 and admit air directly into the chamber 22. If both of the means described are provided, the closing of the valve promptly upon the discharge of a carrier is doubly insured. One or the. other of these means might be eliminated, if desired.

While a specific embodiment of the invention has been described in considerable detail, it will be understood that this is for the purpose of illustration only and is not intended to limit the scope of the invention. Various modifications may be made to suit particular circumstances. The principle of the invention might be employed in connection with a pressure system as well as with the vacuum system illustrated.

What I claim is:

1. In a pneumatic tube system a tube for transmitting a carrier from one point to another, a closure for the delivery end of the tube, means for latching said closure in closed position, means controlled by the carrier as it passes a predetermined point for releasing said latching means, and means for retaining said latching means in released position until the carrier is discharged and the closure restored to closed position.

2. In a pneumatic tube system a tube for transmitting a carrier from one point to another, a closure for the delivery end of the tube, means for latching said closure in closed position, pneumatic means connected with said latching means for operating the same, means controlled by said carrier as it passes a predetermined point for controlling said pneumatic means, and means controlled by said closure for controlling said pneumatic means.

3. In a pneumatic tube system a tube for transmitting a carrier from one point to another, power means connected with said tube, a closure for the delivery end of the tube, a latch for retaining said closure in closed position, pneumatic means for operating said latch, and means in the path of said carrier for controlling said pneumatic means.

4. In a pneumatic tube system a tube for transmitting a carrier from one point to another, power means connected with said tube, a closure for the delivery end of the tube, a latch for retaining said closure in closed position, pneumatic means for operating said latch, means connecting said pneumatic means with said power means to retain the latch in effective position, and means for admitting air to one side of said pneumatic means as the carrier passes a predetermined point to release said latch.

5. In a pneumatic tube system a tube for transmitting a carrier from one point to another, power means connected with said tube, a closure for the delivery end of the tube, a latch for retaining said closure in closed position, pneumatic means for operating said latch, means connecting said pneumatic means with said power means to retain the latch in effective position, means for admitting air to one side of said pneumatic means as the carrier passes a predetermined point to release said latch; and means for admitting air to said side of the pneumatic means so long as the closure is open.

6. In a pneumatic tube system a tube for transmitting a carrier from one point to another, power means connected with said tube, a closure for the delivery end of the tube, a latch for retaining said closure in closed position, pneumatic means for operating said latch, spring means normally urging saidlatch into released position, means connecting said pneumatic means with said power meansto retain the latch in effective position,.and means for admitting air to one side of said pneumatic means as the carrier passes a' predetermined point to release said latch, 1 a a '7. In a pneumatic dispatch system'a transmission tube, power means for providing a carrier propelling air fiow'through said tube. a power control valve, means for automatically opening said valve upon thev insertion of a carrier in said tube, a closure for the discharge end of said tube, and means engaged by the carrier as it passes a given point for simultaneously causing the opening of saidclosure and the closing of said valve by pneumatic means. a

8. In a pneumatic dispatch system a transmission tube, power means for providing a carrier propelling air flow through said tube, a power control valve, means for automatically opening said valve upon the insertion of a carrier in said tube, a closure for the discharge end of said tube, a latch for said closure, and means operated as the carrier approaches said closure for controlling the release of said latch and the closing of said valve. i

9. In a pneumatic dispatch system a transmission tube, powermeans for providing a carrier propelling air flow through said tube, a power control valve, pneumatic means for opening said Valve upon a drop in pressure in said tube, a closure for the discharge end of said tube, a latch for said closure, a second pneumatic means for controlling said latch, said second pneumatic means being operated by said power means to retain the latch in active position, and means operated as the carrier approaches the closure for admitting air to both of said pneumatic means to close said valve and release the latch.

10. In a pneumatic dispatch system a trans mission tube, a closure for the discharge end of said tube, a latch for said closure, pneumatic means for controlling said latch, a pipe arranged to admit air to said pneumatic means for controlling the same, a pair of valves for controlling said admission of air, connections from said closure for operating one of said valves, and means operated by a carrier approaching said closure for controlling the other of said Valves.

11. In a pneumatic tube system a tube for transmitting a carrier from one point to another, means for closing the delivery end of the tube to prevent the free escape of air therefrom, means for locking said closing means in closed position, means actuated by the carrier for releasing the locking means after the speed of the carrier has been retarded by compression of air at said delivery end, and means for retaining said locking means in released position until the carrier is discharged and the closure restored to closed position.

12. In a pneumatic tube system a tube for transmitting a carrier from one point to 'another, a closure arranged to close the delivery end of the tube to provide an air cushionfor said carrier, means for latching said closure in closed position, means actuated bythe carrier after its speedis retarded by said air cushion for releas- "ing said latching means, and means for retaining said latching means inrreleased position until 7 connected directly to said pneumatic means, said pneumatic means being connected to saidcpower means to maintain said valve open while a carrler is passing along the tube, and means engaged by the carrler'as' it passes a given point in the tube for causing opening of said conduittto the atmosphere thereby promptly closing the valve.

14. In a pneumatic tube system,'a tube for transmitting a carrier from one point to another, power means connected to .saidftube for providing a carrier propelling flow of air therethrough, a valve for controlling the flow of air produced by said power means, means connected to said power means constituting the sole means forholding said valve open by the pneumatic force of said powerimeans, and means actuated by movement of the carrier through the 'tube at a'point near the'discharge end of said'tube for subjectingsaid holding means directly to atmospheric pressure ;to interrupt said pneumatic force acting between said holding means and power means and to close the valve promptly.

15. In a pneumatic'tube system, a tube for transmitting a carrier, a source of suction; means connecting said source to said tube for moving carriers therethrough, a valve in said connecting means, means connected to saidsuction source for holding said valve open while a carrier is'in transit, and means engaged by the carrier; near the discharge end of said tube for causing air to 'be admitted into said holding means to break the suction and close said valve.

16. In a pneumatic tubesystem' a tube for transmitting a carrier from one point to another, power means connected to said tube for providing a carrier propelling flow of air therethrough, a valve for controlling said power means, pneumatic means for operating said valve, said pneumatic means being connected to said power means to maintain said valve open While a carrier is passing along the tube, means actuated by a pneumatic impulse from a'moving carrier for causing the closing of said valve, and

means engaged by the carrier in the tube for rendering said pneumatic holding means inefiective to ensure closing of said valve. 7

a 17. In a pneumatic tube system, a tube for transmitting a carrier from one point' to another, power means connected to said tube for providing a carrier propelling flow of air there through, a valve for controlling the flow of air produced by said power means, means connected to said power means for holding said valve open by the pneumatic force of said power means;

means actuated by a rush of air following a moving carrier for interrupting the pneumatic connection between said holding means and power means to close said valve, and'means arranged to be subsequently engaged by said carrier for causing interruption of ,said pneumatic force to ensure closing of said valve.

JOSEPH M. SCANLAN. 

